The present invention relates to a ratchet wrench and, more particularly, to a ratchet wrench with three operational positions.
U.S. Pat. No. 7,278,339 discloses a reversible ratchet wrench including a head rotatably receiving a drive member. A pawl is slideably received in the head between two positions and releasably engages with the drive member. A ring is mounted around an end of the drive member and includes a tip piece having a slot. A reversing plate is pivotably mounted to the end of the drive member and operatively connected to the ring to turn therewith. A switching member is pivotably received in a receiving hole of the head and includes a protrusion engaged in the slot of the tip piece of the ring such that the switching member is pivoted when the ring is pivoted. The switching member includes a receptacle receiving an elastic element and a pressing member biased by the elastic element to press against the pawl. The reversing plate is pivotable between two operative positions to move the pawl between the two positions to switch the driving direction of the ratchet wrench. However, the pivotal axis of the ring coaxial with the rotating axis of the drive member is not coaxial to the pivotal axis of the switching member that is coaxial with the receiving hole. Thus, movement between the ring and the switching member for switching the driving direction of the ratchet wrench is complicated, and the driving direction-switching operation may be unreliable. Furthermore, movement of the protrusion of the switching member for moving the pressing member must compress the elastic member to avoid interference with movement of the pawl. As a result, the driving direction-switching operation may not be smooth. Further, a large number of components are required. Further, the switching member would require an additional space in the head when a third operational position is needed, leading to limitation of designs of the ratchet wrench.
Thus, a need exists for a ratchet wrench with three operational positions having fewer components while allowing smooth, reliable driving direction-switching operation.